Two US senators said on Sunday that Israel’s recent strikes on Syria show that the regime in Damascus is vulnerable, and a former ambassador to the UN said Washington was leaning toward okaying airstrikes against Syria.

Speaking on “Fox News Sunday,” Senator John McCain (R-AZ) said that Syrian President Bashar Assad’s air defense systems were not impenetrable. McCain also criticized President Barack Obama’s handling of the Syrian situation, saying that the red lines the president drew at chemical weapons “were a green light to Bashar Assad to do anything short of that.”

“Apparently, the Syrians and Iranians have crossed a red line with the Israelis,” McCain said. “And that means that weapons of an advanced nature — probably missiles — have been moved from Iran into Syria with intentions of moving them to Hezbollah.”

McCain added that “unfortunately, the red line that the president of the United States [has] was apparently written in disappearing ink.”

On NBC’s “Meet the Press,” Senator Patrick Leahy (D-VT) made similar comments about the Syrian air defense system. Leahy said that the US should arm pro-Western rebels in Syria trying to topple the Assad regime.

Bill Richardson, a former ambassador to the United Nations and governor of New Mexico told ABC’s “This Week” that Israel’s actions had sent a signal to Iran, Hezbollah and possibly the US that the situation was worsening, and that there could be limited US military action in the coming days.

However, he said that Obama was leaning toward an air operation and would not send troops into Syria.

McCain said that the US should intervene in Syria, but by arming the rebels and with “no American boots on the ground.”

Israel’s recent airstrikes on Syria ”will probably put more pressure on this administration” to act, McCain opined.

“We need to have a game-changing action,” McCain said. “And that is no American boots on the ground,

According to McCain, in transferring weapons to Hezbollah, Syria crossed another “red line.”

Representative Peter King (R-NY), however, cautioned against arming the Syrian rebels. “Al-Qaeda elements have a lot of control within the rebel movement,” King said on CNN’s “State of the Union.” “If we are going to arm the rebels, we have to make sure those arms are not going to end up in the possession of al-Qaeda supporters.”